1. Technical Field
The present invention relates to an oscillation module, an electronic device, and a moving object.
2. Related Art
JP-A-2004-040509 discloses an oscillation circuit including: a differential amplifier for oscillation configured with an ECL line receiver; a differential amplifier for feedback buffering which is configured with an ECL line receiver and in which an output terminal is terminated due to emitter terminating resistance; a switch circuit; a voltage-controlled phase-shift circuit; a SAW resonator having a predetermined resonance frequency; and an impedance circuit, in which a positive feedback oscillation loop is formed with at least the differential amplifier for oscillation, the differential amplifier for feedback buffering, the voltage-controlled phase-shift circuit, and the SAW resonator. According to this oscillation circuit, the emitter terminating resistance of the differential amplifier for feedback buffering is changed to increase a drive level of the SAW resonator, and accordingly, the amplitude of a signal from the SAW resonator is relatively greater than that of the noise superimposed thereon. That is, since a large SN ratio is obtained, it is possible to decrease jitter caused by noise superimposed on the signal from the SAW resonator.
This oscillation circuit outputs an oscillation signal at a frequency close to a resonance frequency of the SAW resonator, but it is possible to generate a signal at a frequency which is N times the frequency described above by providing a multiplication circuit at a subsequent stage. JP-A-2007-013565, for example, discloses an oscillation circuit in which a multiplication circuit is provided at a stage subsequent to a ring oscillator. This multiplication circuit has a configuration of outputting an exclusive OR of two signals extracted from inverters in any two stages among inverters of odd stages configuring the ring oscillator, and when the multiplication circuit disclosed in JP-A-2007-013565 is provided at a stage subsequent to the oscillation circuit disclosed in JP-A-2004-040509, for example, it is possible to obtain a multiplied output while preventing an increase in circuit area.
However, noise may be superimposed on power supplied to the multiplication circuit due to an oscillation operation of the oscillation circuit, and an oscillation signal output by the multiplication circuit may be significantly degraded due to the effect of this power supply noise.